Nonlinear Response of Stiffened Panel Suffered from Thermo-Acoustic Loadings

Abstract

The surface protection systems of aerospace and aircraft are often constructed from discretely stiffened panels to support high thermal acoustic loadings. In actual use, the stiffened panels are often subject to compression, shear and combination of compression and shear loads, bucking instability is the most common failure mode. The analysis of the snap-through process of stiffened panel is always a challenge in the word. This paper studied mainly about the non-liner response of the steel stiffened-plates under combined loads of thermal and acoustic. Firstly, the nonlinear balance equation of bucking process is analysised and a improved arc-length method is introduced . Than the FEM numerical method is used to analysis the nonlinear response of a simply supported stiffened panel under different thermal acoustic loadings. The modal frequency and the vibration displacement and stress are calculated. The displacement power spectrum density is analyzed emphatically. Base on the calculated resulted results, the relationship of the fundamental response frequencies versus temperatures is analyzed comparatively, furthermore, the bucking and snap through response characteristics are discussed as well.